Improvement in detached-lever escapements



S. B. TERRY.

y Detached-Lever Escapements. No, lOO, PatentedJuIyLlS-ZB.

Me., ff/... J 55.5.4

UNITED STATE-s PATENT OFFICE.

SILAS B. TERRY, OF WATERBURY, CONNECTICUT, ASSIGNOR TO THE TERRY CLOCK COMPANY, OF SAME PLACE.

IMPROVEMENT IN DETACHED-LEVER ESCAPEMENTS.

Specification forming part of Letters Patent No, 140,560, dated July 1, 1873; application filed December 20, 1872.

To all whom it may concern:

Be it known that I, SrLAs B. TERRY, of Waterbury, in the county of New Haven and State of Connecticut, have invented a new Improvement in Clock-Movements; and I do hereby declare the following, when taken in connection with the accompanying drawings and the letters of' reference marked thereon, to be a full, clear, and exact description ofthe same, and which said drawings constitute part of this specification, and represent in Figure l, afront view of the movement, the front plate of the frame removed to show the improvement; Fig. 2, a side view, parts of the movement broken away to more clearly show the improvement; and in Figs. 3 and 4, detached views enlarged.

This :invention relates to an improvement in that class of clock-movements which are designed to run in any position, and commonly called marine or balance clock-movements and it consists in making the arm of the lever elastic and arranged in the same plane with the axis of the balance, so that the balance in its rotations throws the lever out of its natural plane as it passes from one extreme to the other, the elasticity of the lever giving an impulse to the balance at each termination of the movement of the lever, and the lever arrested so soon as a sufficient impulse has been given to leave the balance free, the momentum of the balance carrying it beyond the movement of the lever so far that when the balance returns it will overcome the elasticity of the lever and carry the lever back past the center on the return movement, and passing the center the lever acts upon the balance as before.

A is the front plate or frame; B, the rear, the two joined by posts C, in the usual manner, the front plate in Fig. l removed, as also some of the wheels of the clock which are not necessary to show the invention. D is the balance-shaft, arranged vertically, having its lower bearing at a; E, the wheel, of any desirable construction; F, the balance-spring, applied to the wheel in the usual or any convenient manner. G is the hub of the wheel,

upon which is arranged a pin, d, extending downward, by which to act in connection with the lever. H is the lever-shaft, arranged below the balanceshaft, but preferably directly in line with that shaft. On this shaft the verge I is arranged and constructed to work in the vergewhee1 L in the usual manner. From the shaft H the lever N extends up to the balance, and is there turned at right angles, and in its end a notch, b', is formed, as seen in Fig. 3. The lever N is made elastic, so that it may be thrown out, as denoted in broken lines, Fig. 2. In the rear ofthe lever, and at each side of the balance-shaft, an arm, P P, extends forward, the end constructed with a notch, as seen in Fig. 3, to receive the lever. Resting in each of the arms, as seen in Fig. 3, the notch of the lever is in the path ofthe movement d, that path being denoted by the broken lines, Fig. 3; hence, starting from the arm I), as the balance rotates, it forces the lever out and past the dead-center f, as denoted in broken lines, Fig. 2. vAfter passing that point the elasticity of the lever- Ythat is to say, the power which it has received but the balancehas received amomentumwhich will carry it beyond that point; then the spring of the balance reacting causes the balance to return, and in its return the reaction of the balance-spring is sufficient to overcome the spring of the lever, hence, when the pin d strikes into the notch of the lever it will carry the lever past the dead-center fand return to its first position on the arm P, imparting a momentum to the wheel, as before.

In this construction the movement of the lever in its connection with the balance is exactly in the path of the movement of the pin upon which it acts, hence the impulse or mo mentum given to the wheel is in exact line of its movement; consequently the pin strikes at the bottom of the notch which is in this path, and avoids the sliding movement or friction of the common lever, and is at the same time as perfectly detached as the common lever.

Momo

By this construction, therefore, the movement :i11ee1i,the stops P and P', constructed :1nd nrrnns very much easier, und :ihn-ge proportion ranged to arrest und hold the snid lever heofthe motive power is dispensed with7 und ai tore the balance has completed its movement lighter spring muy be used. iu either direction, substantially as described. I claim as inyinventioir- SILAS B. TERRY. In combination with the detached lever N, /tnesses made elastic, and its axis of vibration at right A. J. TIBBITS,

angles to the axis ofthe balance, and the huh J. H. SHUMWAY. 

